Hydraulic clamp for rotary car dumpers



Sept. 1, 1931. H. c. HEATON ET AL HYDRAULIC CLAMP FOR ROTARY CAR DuMPERs Filed May '1. 1928 5 Sheets-Sheet 1 'Sept l, 1931. H. c. HEATON ET AL.l 'SZZW HYDRAULIC CLAMP FOR ROTARY CAR DUMPERS Filed May 7, 1928 5 Sheets-Sheet 2 f 7 fly Cla GL Sept. 1, 1931. H. c. HEATON ET AL HYDRAULIC CLAMP FOR ROTARY CAR DUMPERS Filed May 7, 1928 5 Sheets-Sheet 3 Sept., l, 1931. H. c. HEATON ET AL.

HYDRAULIC CLAMP FOR ROTARY CAR DUMPERS Filed May 7. 1928 5 Sheets-Sheet 4 Sept. l, 1931. H. c. HEATON ETLAL 1,821,27

HYDRAULIC CLAMP FOR ROTARY CAR DUMPERS Filed May 7, 1928 5 sheets-sheet 5 latented Sept. 1i, 193

iii-N f HERMAN C. HEAT'NAND FRANK H. ARMSTRGNGQOF CHCAGO, ILLINGIS, ASSIGNORS T LNK BELT COMPANY, OF CH1CAG3,-ILLT,NO1S, A CGRPORTION 0F ILLINOIS HYDRAULIC etnias Pic-rear oan'nuivrrnns Applcaticn filed May panying drawings, wherein- Figure 1- is a side elevation; y Figure 2 is av section on line Q-Qof Figure l; l

Figure 3)` is a section on line 3-3 ot Figure v1;

Figure 4 is a section along the same line as Figure 3 but showing the cradle in the car dumping position;

Figure 5 is a detail, part in elevation and 'part-in section, ofthe valve and control mechanism for one of the-clamps;

Figure 6 is an enlarged detail view of ratchet and pawl arrangement for holding the car; l

Figure 7 is a detail showing-the operating cams and levers. y

Like parts are ind'cated by like-characters throughout the specification afnd drawings.A

In general, our car dumper is equipped with eight separatecast-steel clamps, carried by the cradle, four on each side of the car. Each clamp is moved along .guides by means of a piston rod and piston, the latter operating in a steel cylinder rigidly secured to the structural steel frame-vvorkoi` the car dumper cradle. The pistons are moved to raise and lower the clamps by a hydraulic fluid supplied under pressure to each cylinder by a .small electrically driven pump mounted on the cradle. The pump. draws the fluid from` a suction or supply itank, discharging it through a pipe to afcontrol valve which distributes the hydraulic fluid through pipelines to both ends of the cylinders, as desired, to move the pistons down or up as 1928.I ySerial No. 2755594; l

the case may be. The fluid discharged'lfrom' i the cylinders is returned to the suction .or supply: tank .for using over and over. The location and shape of the supply tank issuch that thepump inlet or suctionis always sub-2 merged in the duid, even whenthecradle is rotated its maximum excursion, or approximately lSOOfromits initial or upright position. Since :the pump-is a centrifugal and not a positive displacementftype, it runs continuously when operating. theidumpe-r,y thus maintaining a pressureon the control valve at all times. The control `valve is operated automatically by al valve lever which engages a iixed cam track on the .dumper foundation, and thereby controls the movements of all clamps in response to the rotation, of the cradle.v

ln the initial or starting vposition of the cradle the clamps are in the raised position ata point above the maximum height of any carwhich may be `dumped by the dumper. Thecontrol valve is held inthe central position,y closing the ports to both: the upperand lower ends of the cylinder by means of a centering device. After the cradle has rotated through an` angle of approximately 10o the valve lever, which is mounted on and rotates with `the cradle, engages the'ixedcam track and moves the valve lever .to one side, admitting fluid under pressure :from the pump. to thetop of the cylinders and permitting escape of Vfluid from the bottom ofthe cylinders, thereby causing the lhydraulic rpressure to draw the clamps down to engage the top of the car. The cam track is so positioned as to hold. the valve open to cause Vpressure to be continuously applied to the holding sides of the pistons until the valve vlever runs off the track after excursion of approximately @90Q fromits starting position.` The centering device then goes into operation, centers the valve lever, and closes-allports to and from the cylinders, thereby locking the clamps against movement in either direction and causing them to support the weight of the car and its contents as the cradle rotates further into the dumping position. y

On' the return movement of the cradle with the empty car at an angle of about 85o'from the initial position, the valve lever again engages the cam track, but since the cradle is rotating in the opposite direction the lever is moved in the opposite direction, opening the ports leading from the holding side of the cylinders to the suction or storage tank and opening the ports leading to the lifting side of the cylinders connecting with the pump. The hydraulic pressure thus is able to raise the clamps from the car and moves them to their initial or uppermost position. At approximately 10 from vertical, the valve lever disengages the cam track, allowing the centering device to again move the valve to its central position and lock the clamps in the upper or released position.

As a precaution against accident due to breaking of a fitting or pipe, some or all of the clamps, preferably the four at the ends of the cradle, are also equipped with mechanically operated pawls. These pawls are pivoted on the clamp guides and are adapted to be thrust into engagement with racks on the backs of the clamps by means of heavy springs, counterweighted levers, etc., which go into operation only after the clamps are seated on the car at about the time when the valve lever is returned to its central position as the cradle approaches the dumping position.

These pawls are forced out of engagement with the racks by mea-ns of a cam lever and cam track system similar to that used for operating the control valve.

The cradle is rotated by means of cables wound about and anchored on the roller rings, the bight of the cable being wound about motor driven drums whereby the cradle may be moved toward and from the dumping position.

A is the foundation for a receiving hopper A1 into which the cars to be unloaded may be dumped. Carried on the foundation are a plurality of pillow blocks A2. Pivoted on each pillow block is an equalizing frame A3 and journaled in each equalizing lever are a pair of rollers A4. 4The cradle has a roller ring A5 at each end of the cradle. These roller rings are supported by and are free to rotate on the rollers A4. Joining these roller rings is a. bridge or frame work As which forms the body of the cradle. A7 are abutments, two on each roller ring; slidable in each abutment are take-up rods A8 supported by springs A2. The cable A10 is anchored at both ends by the take-up rods A2, extends around the flange A11 of the roller ring and intermediate its ends is wound about the drum A12. Each drum is rotated by a gear train A13 from a shaft A14. This shaft is driven through a reduction gear A15 by an electric motor A16. This motor may be controlled in any suitable manner to sta-rt, stop and reverse it to control the rotation of the cradle. A17 is the solenoid brake, automatically controlled by electric current to the motor, whereby the cradle may be locked in position when the current is shut 0H from the motor.

B is the transversely movable transfer table having rollers B1 adapted to travel on tracks B2 on the cradle. B3 are springs normally yielding, forcing the transfer table toward the left as shown in Fig. 2. B4 is an abutment on the foundation, at each end of the cradle. At each end of the transfer table is a lug B5 carrying a roller BG adapted to engage the abutment Bl when the cradle is in the upright position to compress the springs B3 and hold the transfer table in its initial position. As the cradle moves in counter-clockwise direction away from the upright toward the dumping position the springs B3 force the transfer table toward the left until the car B7 on the tracks BS has moved7 by the combined influence of the springs B3 and the force of gravity, into a position such that the side of the car engages the block B9 on the side of the cradle; reference to Fig. l will show the car in such position. Further rotation of the cradle causes the roller BG to be raised out of engagement with the abutment B4. On the return movement the operation is the reverse and engagement of the roller BG with abutment B4 forces the transfer table back to its initial position.

Arranged on opposed sides of the cradle are horizontal clamp guides C, C1. Movable horizontally along the guides C are clamps C2, C3 and along the guides C1 are clamps C1, C5. In so far as their clamping effect is concerned, the clamps C2, C4 and C3, C5 are identically the same, the only difference being that the clamps C2, C3 have upward extensions CG associated with the longer guides C for a purpose hereinafter to appear. The clamps C3, C5 have relatively short overhanging, car-engaging shoulders C7. These shoulders are short because the left-handed side of the car is always in engagement with the cushion B9 and, no matter how wide the car is, the clamp shoulder needs to be only wide enough to overhang the side of the car. The clamps C2, C4, however, have relatively wide car-engaging clamping shoulders C8, these being necessitated by the fact that the position of the side of the cai` engaged by them varies with the width of the car and it is necessary that they be long enough to overhang and hold the narrowest car which is likely to be spotted on the cradle.

Associated with each of the clamps is a hydraulic cylinder C9, there being one for each clamp. Each cylinder contains a piston C10, driving a piston rod C11 which operates one clamp, there being a knuckle joint C12 interposed between the piston rod, a clamp to take care of any inaccuracy, eX-

pansion, contraction or play of the structure -ways in operation.

and to prevent binding.l C13 is a packing gland through which the piston rod travels as it projects from and is withdrawn into the cylinder.

D is a suction tank or reservoir. Associated with it is an electrically operated pump D1 adapted to draw hydraulic motive fluid from the tank through the pipe D2. The tank D is supported on brackets D3, D4, and is always substantially full, as therefore, the intake of the pipe D2 is always below the level of the fluid in the tank, independent of the angular positionv of the cradle, so that the pump is able -to draw mo- --tive fluid from the tank at all times during the operation of the dumper. This pump is preferably a centrifugal and Anot positive displacement pump, and therefore when the dumpcris being operated the pump is al- The pump discharges motive fluid under pressure through the pipe D5 to the control valve housing D0. This valve housing contains a slidable piston valve D1. rShe pipe D5 discharges into the housing through a port D8 intermedi ate the two ends of the piston valve. The ends of the cylindrical valves seat discharge through pipes D0, D-10 to a return pipe D11, which in turn discharges to the tank D at a point above` intake end of the pipe D2. D12 is the breather pipe for the tank. The piston valve D7 isl controlled by the valve stem D13 ei:- ten ding out through a packing gland D14 in the elbow of the pipe D10. At will be noted that the pipes D0, D10, D11 through which motive fluid travels from the valve to the reservoir at low pressure are each larger than the pipe D5 through which motive fluid travels from the pipe to the valve in high pressure.

Leading from the upper end of each of the cylinders C0 is the relatively small high pressure pipe E. Each of these pipes extends downward along the cylinder and communic-ates with the piping E1, which piping in turn communicates with a main pressure pipe E2 extending along the cradle. This main pipe is located at one side of the cradle only, so that the pipe system E1 leading from it f to the pipes E has elements of various length to communicate with the pipes associated with the cylinders on the far side of the cradle. This pipe E2 communicates by means of a nipple E3 with the port E4 in one end of the i valve cylinder. E5 is a port at the other end of the valve cylinder communicating with a relatively large pipe E15, from which lead branches, one to the lower end of each of the cylinders. It will be noted that thus there are two piping systems communicating, respectively, with the upper and lower ends of the cylinders and with opposed ends of the piston valve seat. The pipes communicating with the upper ends of the cylinders are smaller thanthose communicating withthe lower ends, the reason for thisbeing that the.

maximum pressure is maintained inthe up,-t per ends of 'the cylinders to force thefpi'stons down and hold the clamps against thev top of the car to hold the kcar and its contents.. lVhile this is going on exhaustvtakes place through the large exhaust pipes, and, since. the pipes are large, free exhaust travel of the hydraulic fluid from the lower ends of the cylinders may take place. Then movcment in the opposite direction occurs vthe pressureis reduced, because it only needs to be great enough to raise the clamps; thus the pipes which receive the exhaust on the lower-` ing movement and carry pressure on the raising movement only can be made larger. Jhen the parts are in the position shown in Fig. 5, both ports E4 and are closed and the hydraulicfluid in the system cannotV circulate. 4Thus the pistons are positively held in they definite positionvthey may have occupied at the time the valve movedto the closed position. If the valve is new moved to the right in Fig. 5, motive fluid ,willbe forced by the pumpthrough the pipe D5 into the portrDS, thence longitudinally along thc valve seat to the port E4, thence through the pipes E2, E1 and E to the upper end of each cylinder. At the same time an exhaust path is opened through the lower ends of cach cylinder, through the pipes E15` and the port E5, thence through the pipes D10, D11 to the reservoir D, to replace the motive fluid drawn therefrom by the pump. This results in mov-- ing each piston downwardly until each individual clamp separately or simultaneously seatson the car. As soon as each clamp is so seated, no further movement of the valvev pis.- ton involved will take place and each clamp will be forced down against the car by a pressure which may be measured in terms of the effective cross-sectional area of the piston multiplied by the hydraulic press-ure. After all the clamps have seated andthe pistons have ceased movement, the centrifugal pump will continue to operate, maintaining the pressure in the system but not displacing any additional hydraulic fluid.

Some time thereafter the valve will be returned to the central position, but new the' pistons will be in a position lower than thaty shown in Fig. 5, depending upon the height pipesE, E1, E2, Eport E4., pipes D0 to the reservoir D, and this will continue until the pistons have heen moved back to the upper position as shown in Fig. 5,y with the clamps raised. Continuing the pump operation will merely maintain the Vpressurein the system ratchet.

and V'holdthe pistons in the upper' position until'the valve is again brought to the central position locking clamps away from the car.

The valve stem D13 is reciprocated by means of a connecting shaft F, Which extends across the cradle as indicated and is pivoted on a lever F1, mounted on the shaft F10, Which carries at one end the control lever F12. This lever is balanced between tension springs F2, F2 anchored on abutments F3, F 1 on the cradle. The results of these tWo springs is to center the control lever and likewise the valve, the position of the lever in Fig. 3 corresponding to the position of the valve shown in Fig. 5. Ii novv the cradle is moved in a counter-clockwise direction from the position shown in Fig. 3, the lever F12 will be rotated in a clockwise direction by engagement of the roller F1 With the cam track F5 and the lever Will be maintained in that position with the valve position to the right in Fig. 5 to permit motive fluid to be supplied to the cylinders to dran7 them down as long as the cam lever and roller F4 remains in contact With the track. As soon as the cam lever and roller travels off the track the valve will be automatically returned to the neutral position, preventing circulation oiz the motive iiuid and holding the clamps in the down position. On the return movement the roller F4 will engage the cam track F5 from the opposite direction and Will be moved in counterclockwise direction, thus moving the piston valve to the left and permitting such a distribution of the motive fluid as Will cause the hydraulic pressure to raise the clamps, thus continuing until the control lever and roller F1 runs oli the track and the centering mechanism brings the valve back to the neutral position.

The relative positions of the lever F12 and roller FAx which control the piston valve D7 are shown in Fig. .7.

G is a saw-tooth ratchet on the back side oi the long clamps at the ends of the cradle.

G1 is a lever pivoted on the clamp side, having at its end a dog G2 adapted to engage the ratchet. G3 is a compression spring associated with a guide pin G4 to a yieldingly held latch in engagement With the ratchet. x5 is a lever pivoted on the shaft G15, said lever being connected by the link G0 With the lever G1 by a'loose connection yoke and pin G7 as indicated. Mounted on one end of the shaft G15 is a lever G10 pivotally connected to a control rod G11 Which extends down along the guide to engage at its other end one arm ot' the lever G0, which levcrcarries a roller G10 adapted to engage the cam track G12. In the upright position of the cradle the roller G10 is in engagement with the cam track G12. It

Will be understood that the spring G3 tends to i force the latch into engagement With the rl`he roller G10 as the cradle moves toward the dumping position is in contact with the track G12 for a predetermined distance. Thus the ratchet and latch are disengaged When clamp movements commence. The roller G10 engages the track G12 and the roller F1 engages the track F5 and leave their tracks simultaneously at the time the hydraulic valve is moved to neutral position. The dogs G2 at the right in Fig. 2 are operated by means oi' the lever G10 associated with the lever G0 and the connecting rod G11 connected by means of a bell crank lever to the control rod G8. It, for any reason, the hydraulic system should become defective after the clamps C2, C0 are seated upon the car and the piston valve D7 is in neutral position, the latches G2 engaging the ratchet G will lock the clamps which hold the car in the dumping 'position until on the return movement the roller G10 engages the cam track G12.

7e claim:

l. In a car dumper, a cradle and means for rotating'it, a plurality of car holding clamps thereon and hydraulic means for moving them toward and from the car and for holding them in car clamping and in released positions, said hydraulic means includinga a separate hydraulic cylinder and piston Ior each clamp and a pump, a distribution valve, a pressure conduit leading from pump to valve, cond .its leading from the valve to both ends of the cylinders and means responsive to the position of the cradle for operating the valve to displace it to distribute iiuid under pressure to one end of the pistons, and permit liow ot exhaust liuid from the other ends of the pistons to move the clamps and the valve operating means comprising a fixed cam track adjacent the cradle and a valve displacing means adapted to be engaged by the cam track during a portion ot the cradle movement and means 'or automatically centering the valve when the valve displacing means are out of engagement with the cam.

2. In a car dumper, a cradle and means for rotating it, a plurality of car holding clamps thereon and hydraulic means 'for moving them toward and from the car and for holding them in car clamping and in released positions, said hydraulic means including a separate hydraulic cylinder and piston for each clamp and a pump, a distribution valve, a pressure conduit leading from pump to valve, conduits leading from the valve to both ends of the cylinders and means responsive to the position of the cradle for operating the valve to displace it to distribute fluid under pressure to one end of the pistons, and permit flow of exhaust Huid from the other ends of the pistons to move the clamps and for moving the valve into neutral position to close both the intake and exhaust passages from the cylinders to positively lock the clamp in place, and the valve operating means comprising a fixed cam track adjacent the cradle and a valve displacing means adapted to be engaged by the cam track during a portion of the cradle movement and means for automatically centering the valve When the valve displacing means are out of engagement With the cam.

3. In a car dumper, a cradle and means for rotating it, a. plurality of car holding clamps thereon and hydraulic means for moving them toward and from the car and for holdm ing them in car clamping'and in released positions, the hydraulic means comprising a cylinder and plunger :for each clamp, the hydraulic system including a single storage reservoir motor driven pump and distribution valve and pipes leading from the distribution valve to both ends of the cylinders, the hydraulic means comprising a reservoir, the pump drawing hydraulic fluid therefrom, a distribution valve, pipes leading therefrom to the cylinders, the reservoir being positioned on the cradle at a point generally above the intake of the pump, the port through Which material passes from the reservoir to the pump being located at a point with respect to the reservoir position that as the reservoir and pump rotate With the cradle toward the dumping position, the liquid level in the reservoir is moved progressively higher and higher, an increased proportion of the reservoir being raised above the discharge port being such that the pump intake is submerged at all times independent of cradle position.

Signed at Chicago, in the county of Cook :g5 and State of Illinois, this 24th day of April,

HERMAN C. HEATON. FRANK I-I. ARMSTRONG. 

